feat(demo): optional GoatCounter tracker for public demo builds

app/vite.config.ts

@@ -1,12 +1,32 @@
 import path from "path"
 import react from "@vitejs/plugin-react"
 import tailwindcss from "@tailwindcss/vite"
-import { defineConfig } from "vite"
+import { defineConfig, type Plugin } from "vite"
+
+// Tracker GoatCounter SOLO en el build de la demo pública (issue #112):
+//   VITE_GC_COUNT=https://stats.helios.cloudless.club npm run build
+// Los builds normales NO lo llevan: una instalación self-hosted nunca debe
+// llamar a casa. Los hits se registran con prefijo /demo en el mismo site
+// que la landing ("/" = landing, "/demo/..." = demo).
+const gcCount = process.env.VITE_GC_COUNT?.replace(/\/$/, "")
+
+function goatcounterPlugin(): Plugin {
+  return {
+    name: "helios-goatcounter",
+    transformIndexHtml(html) {
+      if (!gcCount) return html
+      const snippet =
+        `    <script>window.goatcounter={path:function(p){return '/demo'+p}}</script>\n` +
+        `    <script async data-goatcounter="${gcCount}/count" src="${gcCount}/count.js"></script>\n  </head>`
+      return html.replace("</head>", snippet)
+    },
+  }
+}
 
 // https://vite.dev/config/
 export default defineConfig({
   base: './',
-  plugins: [react(), tailwindcss()],
+  plugins: [react(), tailwindcss(), goatcounterPlugin()],
   server: {
     port: 3000,
   },

server/src/index.js

@@ -227,13 +227,16 @@ app.post('/api/update/apply', async (c) => {
 
 
 // Security headers middleware
+// GC_ORIGIN (solo demo pública, issue #112): origen extra permitido en CSP
+// para el tracker GoatCounter. Las instalaciones normales no lo definen.
+const gcOrigin = process.env.GC_ORIGIN ? ` ${process.env.GC_ORIGIN}` : ''
 app.use('*', async (c, next) => {
   c.header('X-Content-Type-Options', 'nosniff')
   c.header('X-Frame-Options', 'DENY')
   c.header('Referrer-Policy', 'strict-origin-when-cross-origin')
   c.header('Permissions-Policy', 'geolocation=(), microphone=(), camera=()')
   c.header('Strict-Transport-Security', 'max-age=31536000; includeSubDomains')
-  c.header('Content-Security-Policy', "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; connect-src 'self' https://api.github.com")
+  c.header('Content-Security-Policy', `default-src 'self'; script-src 'self' 'unsafe-inline'${gcOrigin}; style-src 'self' 'unsafe-inline'; connect-src 'self' https://api.github.com${gcOrigin}`)
   await next()
 })
 const sseClients = new Set()